Normal air diffusion reduces tire pressure over time. The natural state of pneumatic tires is under inflated. Accordingly, drivers must repeatedly act to maintain tire pressures or they will see reduced fuel economy, tire life, and/or reduced vehicle braking and handling performance. Tire pressure monitoring systems have been proposed to warn drivers when tire pressure is significantly low. Such systems, however, remain dependant upon the driver taking remedial action when warned to re-inflate a pneumatic tire to the recommended pressure. It is a desirable, therefore, to incorporate a self-inflating feature within a pneumatic tire that will self-inflate the tire in order to compensate for any reduction in tire pressure over time without the need for driver intervention.